By CA Anil K. Jain ,Chartered Accountant | Macro – Economist
| Policy Researcher | Author 
President – Ahimsa Foundation India

River water recharge
wells technology in Australia—known as Managed Aquifer Recharge (MAR)—is an
innovative approach to water security. The system captures seasonal high flows
from rivers, treats the surface water, and injects it through boreholes directly
into underground aquifers for long-term storage and later recovery.

Australia primarily
employs two injection well configurations:

• ·        
  Aquifer Storage and Recovery (ASR): Uses
  the same well for both injection and extraction.
• ·        
  Aquifer Storage Transfer and Recovery
  (ASTR): Uses separate injection and extraction wells spaced a specific distance
  apart to ensure the water spends a set amount of time underground for natural
  filtration.

Historical
Background

Australia’s development
of river recharge wells spans four key phases:

• ·        
  1960s (Pioneer Phase): The technology
  began in 1965 in the Burdekin Delta, Queensland. Severe groundwater pumping for
  sugarcane farming was causing the water table to drop and sea water to seep
  inland. Local authorities began diverting river water into channels, basins,
  and shallow recharge spear wells.
• ·        
  1970s to 1980s (Agricultural Expansion):
  Grape growers in South Australia’s Angas-Bremer region faced falling water
  tables and rising salinity. Farmers built gravity-fed recharge wells to funnel
  winter floodwaters from local rivers deep into limestone aquifers.
• ·        
  1990s to 2000s (Urban ASR and ASTR
  Innovations): Prolonged droughts led the City of Salisbury in South Australia,
  alongside the Commonwealth Scientific and Industrial Research Organisation
  (CSIRO), to pioneer urban ASR and ASTR systems. They combined artificial
  wetlands for pre-treatment with deep injection wells.
• ·        
  2009 to Present (National Standards):
  Australia established the Australian Guidelines for Managed Aquifer Recharge
  under the National Water Initiative. This created a standardized
  risk-management framework for water quality, environmental safety, and groundwater
  rights.

How the Technical System
Works

• ·        
  River Intake and Pre-Treatment: Raw river
  water contains silt and organic matter that can clog underground wells. Water
  is diverted into settling basins or constructed wetlands where suspended solids
  settle and natural biological processes lower turbidity.
• ·        
  Pressurised Well Injection: Water is fed
  into the aquifer using specialised downhole control valves. These valves keep
  positive pressure inside the pipe to prevent air bubbles from entering, which
  stops chemical reactions that cause mineral clogging.
• ·        
  Aquifer Storage: Water forms a fresh
  storage “bubble” within unconfined sand layers or deep limestone rock
  formations.
• ·        
  Clogging Prevention and Maintenance: To
  keep wells clear, operators perform routine backwashing (pumping water out at
  high speed for 15 to 30 minutes) to flush out accumulated sediment and
  biological film.
• ·        
  Recovery Pumping: Submersible pumps
  extract the stored water during dry months or droughts for irrigation,
  industrial, or municipal use.

Major
Projects and Operational Details

1. Burdekin Delta
(Queensland)

• ·        
  Location: Near Ayr and Home Hill in North
  Queensland.
• ·        
  Source Water: Burdekin River.
• ·        
  Aquifer Type: Unconfined alluvial sand and
  gravel.
• ·        
  Storage and Scale: Recharges between
  40,000 and 100,000 megalitres annually across more than 150 kilometers of
  channels, pits, and recharge wells.
• ·        
  Success and Impact: Australia’s oldest
  scheme has successfully halted coastal saltwater intrusion for over 60 years
  and supports one of the nation’s most productive sugarcane regions.

2. Angas-Bremer Basin
(South Australia)

• ·        
  Location: Langhorne Creek wine region,
  south of Adelaide.
• ·        
  Source Water: Angas River, Bremer River,
  and winter River Murray allocations.
• ·        
  Aquifer Type: Semi-confined Tertiary
  limestone (30 to 60 meters deep).
• ·        
  Storage and Scale: Recharges 2,000 to
  7,000 megalitres per year using over 60 gravity-fed recharge wells.
• ·        
  Success and Impact: Over 30 years of
  operation lowered regional groundwater salinity from over 5,000 mg/L down to
  under 1,500 mg/L in localized storage areas, securing reliable irrigation for
  high-value vineyards.

3. City of Salisbury and
Parafield Airport Network (South Australia)

• ·        
  Location: Northern metropolitan Adelaide.
• ·        
  Source Water: Little Para River, local
  creeks, and urban stormwater.
• ·        
  Aquifer Type: Confined Tertiary limestone
  (150 to 200 meters deep).
• ·        
  Storage and Scale: Operates 12 MAR sites
  with a total storage capacity exceeding 15 gigalitres.
• ·        
  Success and Impact: The Parafield Airport
  site uses an advanced ASTR system with 6 injection wells surrounding 2 recovery
  wells spaced 50 meters apart. This design guarantees at least one year of
  underground residence time, allowing soil microbes to naturally clear out
  pathogens. Recovered water feeds a non-potable distribution network that
  supplies over 70% of the local council’s non-drinking water needs.
  

4. Murrumbidgee
Irrigation Scheme (New South Wales)

• ·        
  Location: Riverina agricultural region,
  NSW.
• ·        
  Source Water: High seasonal flows from the
  Murrumbidgee River.
• ·        
  Aquifer Type: Deep alluvial sand and
  gravel formations.
• ·        
  Storage and Scale: Recharges 3,000 to
  10,000 megalitres per year.
• ·        
  Success and Impact: Acts as an underground
  drought insurance bank for broadacre farming, allowing farmers to store surplus
  allocations during wet years and pump them back during dry seasons.

Key Advantages and
Success Factors

• ·        
  Zero Evaporation Loss: Surface dams in
  inland Australia can lose up to 2.5 meters of water depth per year to heat and
  evaporation. Aquifer storage experiences zero evaporation loss.
• ·        
  Natural Filtration: Storing water
  underground eliminates harmful pathogens like E. coli and Cryptosporidium
  within 20 to 50 days due to natural microbial activity and lack of sunlight.
• ·        
  Land Space Efficiency: Storing water
  underground frees up valuable surface land that would otherwise be submerged by
  traditional dams.
• ·        
  Salinity Control: Injecting fresh river
  water displaces salty groundwater, creating a usable freshwater buffer for
  surrounding agriculture.